For millions of us, winter weather has already started. As the winds howl, the snow flies and the temperatures drop, the National Weather Service issues various levels of alerts for wintry weather ...

The National Weather Service has issued a Cold Weather Advisory for the entire region. The advisory will go into effect Monday, Jan. 20, at 1 a.m. until Wednesday, Jan. 22, at 10 a.m.

A weather warning can be issued for events including tornadoes, hurricanes and blizzards. Here’s what makes people act on — or ignore — those messages.